US3090236A - Temperature indicating devices - Google Patents

Temperature indicating devices Download PDF

Info

Publication number
US3090236A
US3090236A US142042A US14204261A US3090236A US 3090236 A US3090236 A US 3090236A US 142042 A US142042 A US 142042A US 14204261 A US14204261 A US 14204261A US 3090236 A US3090236 A US 3090236A
Authority
US
United States
Prior art keywords
separator
temperature
tube
substance
temperature indicating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US142042A
Inventor
Nicol Donald Laurence
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
National Research Development Corp UK
Original Assignee
National Research Development Corp UK
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by National Research Development Corp UK filed Critical National Research Development Corp UK
Application granted granted Critical
Publication of US3090236A publication Critical patent/US3090236A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K3/00—Thermometers giving results other than momentary value of temperature
    • G01K3/02—Thermometers giving results other than momentary value of temperature giving means values; giving integrated values
    • G01K3/04—Thermometers giving results other than momentary value of temperature giving means values; giving integrated values in respect of time
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
    • G01K11/06—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using melting, freezing, or softening
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
    • G01K11/12—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in colour, translucency or reflectance
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K5/00—Measuring temperature based on the expansion or contraction of a material

Definitions

  • a temperature-indicating device which will give a visual indication of its temperature having reached a given value and which will continue to give this indication even if its temperature subsequently falls below the given value, comprises a closed vessel of such composition (and wall thickness) that the colour of its contents may be seen, which is divided into separate compartments by a separator composed of a substance which melts at the temperature whose attainment is to be indicated, the separate compartments containing substances which are liquid at the temperature whose attainment is to be indicated and which upon mixing with each other in the event of the separator being melted will produce a substantially permanent coloration dissimilar from any coloration observable when the separator is intact, the substance of which the separator is composed being insoluble in and non-reactive with the liquids which it is to separate.
  • said substances which are liquid at the temperature whose attainment is to be indicated are such that when they react they form a flocculent precipitate.
  • One advantage of this optional feature of the invention is that the large particles formed by the reaction of the two substances would ensure that any difiusion which occurs through the solid separator would not continue as the large solid particles would fill up any gaps in the separator and prevent further diffusion.
  • the liquids which produce the dissimilar coloration upon mixing should be aqueous solutions, and in this case the substance of which the separator is composed must be insoluble in water. It is also preferable (though not essential) that the density of the substance of which the separator is composed should be lower than that of water. If the device is intended for use at temperatures below the freezing point of water, then ethyl alcohol or ethylene glycol or some other suitable substance may be added to the aqueous solutions in a 50/50 mixture of alcohol or glycol and water just mentioned in order to ensure that they are still liquid at the temperatures in question; in this case the substance of which the separator is composed must be insoluble in aqueous alcohol or whatever mixture is used.
  • Hydrocarbons are particularly useful substances of which to form the separators, and the following are some specific examples with their melting points (i.e. the temperatures which they may be used to indicate):
  • sodium carbonate with sodium hydroxide is advantageous in that Whereas sodium hydroxide mixed with cobalt nitrate normally gives a blue precipitate which turns brown in a matter of hours, if sodium carbonate is present it remains blue for very long periods.
  • the vessel itself may for instance be a closed tube of polyethylene, a plasticised polyvinyl chloride composition, or another synthetic resin or synthetic resin composition.
  • a preferred form of tube is one made of plasticised P.V.C. As the separator does not adhere well to P.V.C., the tube preferably contains a glass lining.
  • P.V.C. gives a high degree of transparency and it is easy to seal.
  • a further advantage of the P.V.C. tube is that there is little or no loss of liquid should the inner glass lining be smashed. Consequently, the temperature indicator can be used close to food without any risk of contamination.
  • the lower end of the tube includes a coloured comparator area such as a spot to indicate the change in colour which will occur when the temperature is reached and the two substances react.
  • a coloured comparator area such as a spot to indicate the change in colour which will occur when the temperature is reached and the two substances react.
  • a solid object such as a ball bearing, or a small glass vball for example, is frozen into the separator.
  • the tube is laid horizontally. With this preferred feature the ball moves on melting of the separator and ensures adequate mixing.
  • FIG. 1 shows a temperature indicator in accordance with the invention
  • a temperature indicator in accordance with the invention
  • a temperature indicator comprising a l capacity glass tube 10 of the type known as at Durham tube as used by bacteriologists which 12 of, say, l-nonanol containing a ball bearing 13 is solidified on top of the solution of lead acetate so as to be about halfway along the tube iii.
  • a second aqueous solution 14 of, say, potassium iodide is then put into the top half of the tube on top of the nonaqueous separator layer.
  • the glass tube is then inserted as a liner in a plasticised P.V.-C. tube 15 and both ends of the P.V.C. tube are sealed leaving a small air gap 16.
  • a coloured insert 17 of the type of material used for P.V.C. covered electric cables is moulded into the sealing portion at the end of the P.V.C. tube, said insert being of the same colour as the colour occurring when the solutions mix.
  • the whole assembly is about 3 /2 to 4" long and the actual P.V.C. covered central area containing the glass tube is about /2 to diameter.
  • the temperature indicator in use is positioned horizontally in, say, a crate of frozen food.
  • Such a device may be made by taking a tube sealed at one end, filling it to a depth of about 1% with the nickel sulphate solution, adding n-dodecane to form a layer about 0.25" deep, placing the tube in a freezing bath or cold store until the n-dodecane (which has a melting point of +12 F.) is frozen, adding the dirnethyglyoxime solution on top of the frozen n-dodecane, and sealing up the tube.
  • the technique just described may be used in making other devices in accordance with the invention if the substance of which the separator is composed has a lower specific gravity than at least one of the two substances in liquid form which it isto separate, and if both of these have a specific gravity lower than the separator substance in liquid form the technique may be modified by freezing the first liquid to be introduced before forming the separator layer. In any case, however, it will he understood that when the device has been prepared it should naturally be stored at a temperature lower than the melting point of the separator substance.
  • a temperature-indicating device in accordance with the present invention may if desired be arranged to indicate more than one temperature.
  • a number of separators with difierent melting points may be used, the various melting points corresponding, as implied by the preceding description, with the various temperatures to be indicated.
  • a temperature indicating device which will give a visual indication of its temperature having reached a given value and which will continue to give this indication even if its temperature subsequently falls below the given value, comprising a closed vessel of such composition and wall thickness that the colour of its contents may be seen, which is divided into separate compartments by a separator composed of a substance which melts at the tempera tu-re WhOSE attainment is to be indicated, the separate compartments containing substances which are liquid at the temperature whose attainment is to be indicated and which upon mixing with each other in the event of the separator being melted will produce a substantially permanent coloration dissimilar from any coloration observable when the separator is intact, the substance of which the separator is composed being insoluble in and non-reactive with the liquids which it is to separate.
  • a temperature indicating device in which the said substances which are liquid at the temperature Whose attainment is to be indicated are such chat when they react they form a flocculent precipitate.
  • a temperature indicating device in which the liquids which produce the dissimilar coloration upon mixing are aqueous solutions and the substance of which the separator is composed is insoluble in water.
  • a temperature indicating device in which the density of the substance of which the separator is composed is lower than that of water.
  • a temperature indicating device in which a freezingpoint depressant is added to the aqueous solutions.
  • a temperature indicating device comprising a vessel having a transpicuous wall, at least one separator dividing said vessel into separate compartments, said separator being composed of a substance which melts at a temperature required to be indicated, and liquids in said compartments which upon mixing change in appearance.
  • a temperature indicating device in which the separator is composed of a hydrocarbon.
  • a temperature indicating device in which the liquids are such that upon mixing they produce a coloration different from any coloration of the unmixed liquids and a comparator is carried by the device of the same colour as that produced by mixing the liquids.
  • a temperature indicating device in which said vessel comprises a closed tube of a synthetic resin composition.
  • a temperature indicating device in which said tube has a glass lining.
  • a temperature indicating device comprising a vessel having a transpicuous Wall, at least one separator dividing the vessel into separate compartments, said separator being composed of a substance which melts at a temperatui'e required to be indicated, and liquids in said compartments which upon mixing produce a distinctive color and a fiocculent precipitate.
  • a temperature indicating device comprising a vessel having a transpicuous wall, at least one separator dividing the vessel into separate compartments, said separator being composed of a substance which melts at a temperature required to be indicated, liquids in said compartments which upon mixing change in appearance, and a solid object in said separator displaceable when the separator melts.
  • a temperature indicating device in which said solid object is a ball.

Description

Filed 001'.- 2. 1961 3,09%,236 TEWERATURE ENDICATHQG DEVICE Donald Laurence Nicol, Hull, England, assignor to Na tional Research Development Corporation, London, EngiantL, a British corporation Filed Oct. 2, 1961, Ser. No. 142,942 Claims priority, application Great Britain Get. 15, 1960 13 Claims. (Cl. 73358) This invention relates to temperature indicating devices.
According to the present invention, a temperature-indicating device, which will give a visual indication of its temperature having reached a given value and which will continue to give this indication even if its temperature subsequently falls below the given value, comprises a closed vessel of such composition (and wall thickness) that the colour of its contents may be seen, which is divided into separate compartments by a separator composed of a substance which melts at the temperature whose attainment is to be indicated, the separate compartments containing substances which are liquid at the temperature whose attainment is to be indicated and which upon mixing with each other in the event of the separator being melted will produce a substantially permanent coloration dissimilar from any coloration observable when the separator is intact, the substance of which the separator is composed being insoluble in and non-reactive with the liquids which it is to separate.
According to a further optional feature of this invention, said substances which are liquid at the temperature whose attainment is to be indicated are such that when they react they form a flocculent precipitate.
One advantage of this optional feature of the invention is that the large particles formed by the reaction of the two substances would ensure that any difiusion which occurs through the solid separator would not continue as the large solid particles would fill up any gaps in the separator and prevent further diffusion.
It is preferable that the liquids which produce the dissimilar coloration upon mixing should be aqueous solutions, and in this case the substance of which the separator is composed must be insoluble in water. It is also preferable (though not essential) that the density of the substance of which the separator is composed should be lower than that of water. If the device is intended for use at temperatures below the freezing point of water, then ethyl alcohol or ethylene glycol or some other suitable substance may be added to the aqueous solutions in a 50/50 mixture of alcohol or glycol and water just mentioned in order to ensure that they are still liquid at the temperatures in question; in this case the substance of which the separator is composed must be insoluble in aqueous alcohol or whatever mixture is used.
Hydrocarbons are particularly useful substances of which to form the separators, and the following are some specific examples with their melting points (i.e. the temperatures which they may be used to indicate):
The invention is by no means restricted, however, to
3-,%,23fi Patented May 21, 1963 the use of hydrocarbon separators, and the following are some specific examples of other substances which may be used, with their melting points:
F. Tertiary butyl chloride 16 Hexyl methyl ketone -6 l-decanol acetate +5 Ethyl hexyl ketone +17 n-Nonanol (n-nonane-1-ol) +23 The substances contained in the separate compartments may for example be a nickel sulphate or other nickel salt solution on the one hand and a dimethylglyoxime solution on the other hand; nickel sulphate solution is pale green and dimethylglyoxime solution is colourless, but upon being mixed the solutions give a red coloration. Another example of a pair of substances which may be present in the separate compartments is provided by lead acetate and potassium iodide solutions; in this case a yellow coloration is formed when the solutions mix, both solutions being colourless so long as they remain unmixed.
The following are preferred pairs of solutions which can be used as said substances and which react to form a flocculent precipitate:
It should be noted that the use of sodium carbonate with sodium hydroxide is advantageous in that Whereas sodium hydroxide mixed with cobalt nitrate normally gives a blue precipitate which turns brown in a matter of hours, if sodium carbonate is present it remains blue for very long periods.
The vessel itself may for instance be a closed tube of polyethylene, a plasticised polyvinyl chloride composition, or another synthetic resin or synthetic resin composition.
A preferred form of tube is one made of plasticised P.V.C. As the separator does not adhere well to P.V.C., the tube preferably contains a glass lining.
Advantages of using P.V.C. are that it gives a high degree of transparency and it is easy to seal.
A further advantage of the P.V.C. tube is that there is little or no loss of liquid should the inner glass lining be smashed. Consequently, the temperature indicator can be used close to food without any risk of contamination.
Preferably the lower end of the tube includes a coloured comparator area such as a spot to indicate the change in colour which will occur when the temperature is reached and the two substances react.
To ensure that the solutions on either side of the separator mix when the separator melts a solid object such as a ball bearing, or a small glass vball for example, is frozen into the separator. In use the tube is laid horizontally. With this preferred feature the ball moves on melting of the separator and ensures adequate mixing.
One embodiment of the invention is diagrammatically illustrated in the accompanying drawing, which shows a temperature indicator in accordance with the invention comprising a l capacity glass tube 10 of the type known as at Durham tube as used by bacteriologists which 12 of, say, l-nonanol containing a ball bearing 13 is solidified on top of the solution of lead acetate so as to be about halfway along the tube iii. A second aqueous solution 14 of, say, potassium iodide is then put into the top half of the tube on top of the nonaqueous separator layer.
The glass tube is then inserted as a liner in a plasticised P.V.-C. tube 15 and both ends of the P.V.C. tube are sealed leaving a small air gap 16. At one end of the P.V.C. tube a coloured insert 17 of the type of material used for P.V.C. covered electric cables is moulded into the sealing portion at the end of the P.V.C. tube, said insert being of the same colour as the colour occurring when the solutions mix.
The whole assembly is about 3 /2 to 4" long and the actual P.V.C. covered central area containing the glass tube is about /2 to diameter.
in use the temperature indicator is positioned horizontally in, say, a crate of frozen food.
If the frozen food is raised above a predetermined temperature at any time the separator layer melts, the
. two aqueous solutions aided by the air bubble and ball bearing and the contents of the tube, instead of being clear and colourless, become yellow and opaque. This provides a permanent indication that the tube, at some time, has been subjected to a higher temperature than the predetermined temperature.
Another specific form of temperature-indicating device in accordance with the invention which may be used for such an application comprises a polyethylene tube about 3" long and about 0.25 internal diameter, divided into two compartments by a layer of firozen n-dodecane, one compartment being filled with -a 1% solution of nickel sulphate in a mixture of water and alcohol in equal parts,
--and the other compartment being filled with a 0.5% solution of dimethyl-glyoxime in a similar water-alcohol mixture. Such a device may be made by taking a tube sealed at one end, filling it to a depth of about 1% with the nickel sulphate solution, adding n-dodecane to form a layer about 0.25" deep, placing the tube in a freezing bath or cold store until the n-dodecane (which has a melting point of +12 F.) is frozen, adding the dirnethyglyoxime solution on top of the frozen n-dodecane, and sealing up the tube. The technique just described may be used in making other devices in accordance with the invention if the substance of which the separator is composed has a lower specific gravity than at least one of the two substances in liquid form which it isto separate, and if both of these have a specific gravity lower than the separator substance in liquid form the technique may be modified by freezing the first liquid to be introduced before forming the separator layer. In any case, however, it will he understood that when the device has been prepared it should naturally be stored at a temperature lower than the melting point of the separator substance.
A temperature-indicating device in accordance with the present invention may if desired be arranged to indicate more than one temperature. In this case a number of separators with difierent melting points may be used, the various melting points corresponding, as implied by the preceding description, with the various temperatures to be indicated. Thus there may for instance be three separators of progressively increasing melting points arranged in an equally-spaced series along the length of a tubular closed vessel, with nickel sulphate solution in the outermost compartment next to the lowest-melting separator and dimethylglyoxime solution in each of the other three compartments; the attainment of the lowest, intermediate and highest temperatures by such a device will be shown by the appearance of a red-coloration along half, threequarters or the whole of the length of the tube respectively.
I claim: 1. A temperature indicating device which will give a visual indication of its temperature having reached a given value and which will continue to give this indication even if its temperature subsequently falls below the given value, comprising a closed vessel of such composition and wall thickness that the colour of its contents may be seen, which is divided into separate compartments by a separator composed of a substance which melts at the tempera tu-re WhOSE attainment is to be indicated, the separate compartments containing substances which are liquid at the temperature whose attainment is to be indicated and which upon mixing with each other in the event of the separator being melted will produce a substantially permanent coloration dissimilar from any coloration observable when the separator is intact, the substance of which the separator is composed being insoluble in and non-reactive with the liquids which it is to separate.
2. A temperature indicating device according to claim 1 in which the said substances which are liquid at the temperature Whose attainment is to be indicated are such chat when they react they form a flocculent precipitate.
3. A temperature indicating device according to claim 1 in which the liquids which produce the dissimilar coloration upon mixing are aqueous solutions and the substance of which the separator is composed is insoluble in water.
4. A temperature indicating device according to claim 3 in which the density of the substance of which the separator is composed is lower than that of water.
5. A temperature indicating device according to claim 3 in which a freezingpoint depressant is added to the aqueous solutions.
6. A temperature indicating device comprising a vessel having a transpicuous wall, at least one separator dividing said vessel into separate compartments, said separator being composed of a substance which melts at a temperature required to be indicated, and liquids in said compartments which upon mixing change in appearance.
7. A temperature indicating device according to claim 6 in which the separator is composed of a hydrocarbon.
8. A temperature indicating device according to claim 6 in which the liquids are such that upon mixing they produce a coloration different from any coloration of the unmixed liquids and a comparator is carried by the device of the same colour as that produced by mixing the liquids.
9. A temperature indicating device according to claim 6 in which said vessel comprises a closed tube of a synthetic resin composition.
10. A temperature indicating device according to claim 9 in which said tube has a glass lining.
11. A temperature indicating device comprising a vessel having a transpicuous Wall, at least one separator dividing the vessel into separate compartments, said separator being composed of a substance which melts at a temperatui'e required to be indicated, and liquids in said compartments which upon mixing produce a distinctive color and a fiocculent precipitate.
12. A temperature indicating device comprising a vessel having a transpicuous wall, at least one separator dividing the vessel into separate compartments, said separator being composed of a substance which melts at a temperature required to be indicated, liquids in said compartments which upon mixing change in appearance, and a solid object in said separator displaceable when the separator melts.
13. A temperature indicating device according to claim 12. in which said solid object is a ball.
lieferences fitted in the tile of this patent UNIT ED STATES PATENTS

Claims (1)

  1. 6. A TEMPERATURE INDICATING DEVICE COMPRISING A VESSEL HAVING A TRANSPICUOUS WALL, AT LEAST ONE SEPARATOR DIVIDING SAID VESSEL INTO SEPARATE COMPARTMENTS, SAID SEPARATOR BEING COMPOSED OF A SUBSTANCE WHICH MELTS AT A TEMPERATURE REQUIRED TO BE INDICATED, AND LIQUIDS IN SAID COMPARTMENTS WHICH UPON MIXING CHANGE IN APPEARNCE.
US142042A 1960-10-15 1961-10-02 Temperature indicating devices Expired - Lifetime US3090236A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3090236X 1960-10-15

Publications (1)

Publication Number Publication Date
US3090236A true US3090236A (en) 1963-05-21

Family

ID=10921480

Family Applications (1)

Application Number Title Priority Date Filing Date
US142042A Expired - Lifetime US3090236A (en) 1960-10-15 1961-10-02 Temperature indicating devices

Country Status (1)

Country Link
US (1) US3090236A (en)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3233459A (en) * 1963-06-11 1966-02-08 Bell Telephone Labor Inc Temperature telltale
US3290669A (en) * 1962-07-28 1966-12-06 Mews Gunter Control device for signalling a predetermined time period of flow of current between two terminals
US3437070A (en) * 1966-01-28 1969-04-08 Lloyd B Campbell Temperature indicator
US3618558A (en) * 1970-05-01 1971-11-09 Barry Tepfer Unsafe condition indicator for frozen food chests
US3868218A (en) * 1971-02-18 1975-02-25 Food Control Methods and devices for automatically activating a chemical process at a given temperature
US3965848A (en) * 1973-10-26 1976-06-29 Becton, Dickinson And Company Fever indicator
US4016762A (en) * 1975-09-02 1977-04-12 Modulus Corporation Temperature indicator
FR2347664A1 (en) * 1976-04-10 1977-11-04 Morishita Jintan Co THERMOMETER MEDICAL TO DISCARD AFTER USE
EP0112023A2 (en) * 1982-11-09 1984-06-27 Minnesota Mining And Manufacturing Company Critical temperature indicator
US4457253A (en) * 1982-11-09 1984-07-03 Minnesota Mining And Manufacturing Company Critical temperature indicator
US5034233A (en) * 1989-12-11 1991-07-23 Mccloy Jr John P Frozen food thaw detector
US5487352A (en) * 1994-09-21 1996-01-30 John R. Williams Temperature indicator for cooked meats
US5695284A (en) * 1994-06-22 1997-12-09 Waters; Gary H. Thaw indicator unit and method of manufacture
US6176197B1 (en) 1998-11-02 2001-01-23 Volk Enterprises Inc. Temperature indicator employing color change
US20060065183A1 (en) * 2004-09-24 2006-03-30 Drummond Scientific Company Sealed-system critical temperature indicator
US20110011330A1 (en) * 2009-07-20 2011-01-20 Drummond Scientific Company Dual-Temperature, Sealed-System Critical Temperature Indicator
ITPD20100040A1 (en) * 2010-02-12 2011-08-13 Davide Zogno DEFROST DETECTOR

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2662018A (en) * 1949-06-14 1953-12-08 Clarence L Smith Frozen food indicator
US2677278A (en) * 1950-03-21 1954-05-04 Smith & Underwood Fusible thermometer
US2856930A (en) * 1957-04-15 1958-10-21 Willard M Huyck Temperature indicator for blood storage container
US2856885A (en) * 1957-04-15 1958-10-21 Willard M Huyck Blood storage temperature telltale

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2662018A (en) * 1949-06-14 1953-12-08 Clarence L Smith Frozen food indicator
US2677278A (en) * 1950-03-21 1954-05-04 Smith & Underwood Fusible thermometer
US2856930A (en) * 1957-04-15 1958-10-21 Willard M Huyck Temperature indicator for blood storage container
US2856885A (en) * 1957-04-15 1958-10-21 Willard M Huyck Blood storage temperature telltale

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3290669A (en) * 1962-07-28 1966-12-06 Mews Gunter Control device for signalling a predetermined time period of flow of current between two terminals
US3233459A (en) * 1963-06-11 1966-02-08 Bell Telephone Labor Inc Temperature telltale
US3437070A (en) * 1966-01-28 1969-04-08 Lloyd B Campbell Temperature indicator
US3618558A (en) * 1970-05-01 1971-11-09 Barry Tepfer Unsafe condition indicator for frozen food chests
US3868218A (en) * 1971-02-18 1975-02-25 Food Control Methods and devices for automatically activating a chemical process at a given temperature
US3965848A (en) * 1973-10-26 1976-06-29 Becton, Dickinson And Company Fever indicator
US4016762A (en) * 1975-09-02 1977-04-12 Modulus Corporation Temperature indicator
FR2347664A1 (en) * 1976-04-10 1977-11-04 Morishita Jintan Co THERMOMETER MEDICAL TO DISCARD AFTER USE
US4457253A (en) * 1982-11-09 1984-07-03 Minnesota Mining And Manufacturing Company Critical temperature indicator
US4457252A (en) * 1982-11-09 1984-07-03 Minnesota Mining And Manufacturing Company Critical temperature indicator
EP0112023A2 (en) * 1982-11-09 1984-06-27 Minnesota Mining And Manufacturing Company Critical temperature indicator
EP0112023A3 (en) * 1982-11-09 1985-05-29 Minnesota Mining And Manufacturing Company Critical temperature indicator
US5034233A (en) * 1989-12-11 1991-07-23 Mccloy Jr John P Frozen food thaw detector
US5695284A (en) * 1994-06-22 1997-12-09 Waters; Gary H. Thaw indicator unit and method of manufacture
US5487352A (en) * 1994-09-21 1996-01-30 John R. Williams Temperature indicator for cooked meats
US6176197B1 (en) 1998-11-02 2001-01-23 Volk Enterprises Inc. Temperature indicator employing color change
US20060065183A1 (en) * 2004-09-24 2006-03-30 Drummond Scientific Company Sealed-system critical temperature indicator
US7475653B2 (en) * 2004-09-24 2009-01-13 Drummond Scientific Company Sealed-system critical temperature indicator
US20110011330A1 (en) * 2009-07-20 2011-01-20 Drummond Scientific Company Dual-Temperature, Sealed-System Critical Temperature Indicator
ITPD20100040A1 (en) * 2010-02-12 2011-08-13 Davide Zogno DEFROST DETECTOR

Similar Documents

Publication Publication Date Title
US3090236A (en) Temperature indicating devices
US3233459A (en) Temperature telltale
DC THE GEOMETRICAL ANALYSIS OF PARTIAL, FUSION
Holtz et al. The water-undersaturated and dry Qz-Ab-Or system revisited. Experimental results at very low water activities and geological implications
EP0112023B1 (en) Critical temperature indicator
US6694913B2 (en) Changed condition indicator
Hess A primary peridotite magma
Turner et al. Fluid motions and compositional gradients produced by crystallization or melting at vertical boundaries
US3859856A (en) Apparatus and method for measuring a temperature
US2971852A (en) Temperature telltale
US5282684A (en) Device for monitoring the temperature of cooled or deep-frozen products
CN102132336A (en) Label for indicating the history of high-temperature exposure
GB1370045A (en) Visual indicator arrangment for monitoring deep-frozen products
GB1419808A (en) Device for indicating used parking time
US4615272A (en) Bomb and bomb liner
US2716065A (en) Telltale for frozen food packages
US7475653B2 (en) Sealed-system critical temperature indicator
US5158364A (en) Method of making and using an improved liquid crystal cumulative dosimeter container
US4038936A (en) Condition change indicator
US2120201A (en) Combination liquid cooler and stirrer
US3437070A (en) Temperature indicator
Simura et al. Mechanism of crystal redistribution in a sheet-like magma body: Constraints from the Nosappumisaki and other Shoshonite intrusions in the Nemuro peninsula, Northern Japan
Montel et al. Characteristics and evolution of" vaugneritic magmas": an analytical and experimental approach, on the example of the Cévennes Médianes (French Massif Central)
CN104330188B (en) One kind is disposable to cross temperature detection method
US3192771A (en) Heat sensitive unit